Compressor unit

Abstract

A compressor unit according to the present disclosure comprises a first compressor, a second compressor, and an oil equalizing pipe and a pressure equalizing pipe that connect the first compressor and the second compressor, wherein the first compressor and the second compressor each comprise: a sealed container; a compression mechanism that is housed in the sealed container and compresses a refrigerant; an electric motor that is housed at a position below the compression mechanism in the sealed container and drives the compression mechanism; and an oil reservoir part that is provided at a position below the electric motor in the sealed container and in which a refrigerator oil is stored. When the region between the electric motor and the oil reservoir part in the sealed container is defined as an electric motor lower region, the oil equalizing pipe communicates with the oil reservoir part of the first compressor and the oil reservoir part of the second compressor, and the pressure equalizing pipe communicates with the electric motor lower region of the first compressor and the electric motor lower region of the second compressor.

Description

Compressor Unit

[0001] The present disclosure relates to a compressor unit in which a plurality of compressors are connected in parallel.

[0002] Conventionally, a compressor unit including multiple compressors connected in parallel by oil equalization pipes has been known. Each of the multiple compressors of the compressor unit includes a compression mechanism that compresses a refrigerant and an electric motor that drives the compression mechanism. The multiple compressors of the compressor unit also include a sealed container that houses the compression mechanism and the electric motor. The electric motor is disposed below the compression mechanism within the sealed container. The sealed container also includes an oil reservoir that stores refrigeration oil below the electric motor. The oil reservoirs of the multiple compressors of the compressor unit are connected to each other by oil equalization pipes. That is, in a compressor unit including multiple compressors connected in parallel by oil equalization pipes, the oil equalization pipes are used to prevent variations in the amount of refrigeration oil stored in the oil reservoirs of the compressors. The refrigeration oil stored in the oil reservoir is supplied to sliding parts of the compression mechanisms, thereby reducing friction and wear of the sliding parts. In addition, a portion of the refrigeration oil stored in the oil reservoir flows out of the compressor of the compressor unit together with the refrigerant compressed by the compression mechanism. The refrigeration oil flowing out of the compressor of the compressor unit circulates through the refrigeration cycle circuit in which the compressor unit is installed and then returns to the compressor of the compressor unit.

[0003] In a compressor unit configured as described above, the outputs of the compressors may be differentiated to control the capacity of the compressor unit. In such a case, a difference in pressure occurs within the sealed containers of the compressors. This difference in pressure within the sealed containers of the compressors also results in a difference in the amount of refrigeration oil stored in the oil reservoirs of the compressors. When a difference in the amount of refrigeration oil stored in the oil reservoirs of the compressors occurs, the amount of refrigeration oil flowing out of the compressor with more refrigeration oil stored in its oil reservoir increases, and the amount of refrigeration oil flowing out of the entire compressor unit also increases. As a result, the amount of refrigeration oil adhering to the heat exchangers of the refrigeration cycle circuit increases, and the heat exchange performance of the heat exchangers of the refrigeration cycle circuit decreases. Furthermore, when a difference in the amount of refrigeration oil stored in the oil reservoirs of the compressors occurs, the amount of refrigeration oil supplied to the sliding parts of the compression mechanism of the compressor with less refrigeration oil stored in its oil reservoir becomes insufficient, resulting in a decrease in the reliability of the compressor.

[0004] For this reason, a conventional compressor unit having multiple compressors connected in parallel by oil equalizing pipes has been proposed in which the multiple compressors are connected in parallel by pressure equalizing pipes and oil equalizing pipes (see Patent Document 1). Specifically, in a conventional compressor unit having multiple compressors connected by pressure equalizing pipes and oil equalizing pipes, the interiors of the sealed containers of the multiple compressors are connected by pressure equalizing pipes. This prevents the pressure difference within the sealed containers of the compressors from increasing when the outputs of the compressors are varied. In other words, a conventional compressor unit having multiple compressors connected by pressure equalizing pipes and oil equalizing pipes prevents the amount of refrigeration oil stored in the oil reservoirs of the compressors from varying when the outputs of the compressors are varied.

[0005] Japanese Patent Application Publication No. 5-133339

[0006] In a conventional compressor unit having multiple compressors connected by pressure equalizing pipes and oil equalizing pipes, the pressure equalizing pipes are connected to a region above the compression mechanisms within the sealed containers of the multiple compressors. That is, in a conventional compressor unit having multiple compressors connected by pressure equalizing pipes and oil equalizing pipes, the pressure equalizing pipes are connected to a region above the electric motor within the sealed containers of the multiple compressors. The electric motor has a flow path that connects the space above the motor with the space below the motor. However, this flow path is narrow, and pressure loss prevents fluid from flowing efficiently through this flow path. Therefore, in a conventional compressor unit having multiple compressors connected by pressure equalizing pipes, even if the pressure difference within the sealed containers of each compressor is reduced by the pressure equalizing pipes, the pressure difference remains large in the oil reservoir located below the electric motor. In other words, conventional compressor units equipped with multiple compressors connected by pressure equalizing pipes and oil equalizing pipes still had the problem of insufficient suppression of variations in the amount of refrigeration oil stored in the oil reservoirs of the compressors when the outputs of the compressors were made different.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a compressor unit having multiple compressors connected by pressure equalizing pipes and oil equalizing pipes, which can reduce variation in the amount of refrigeration oil stored in the oil reservoirs of the compressors more than ever before.

[0008] A compressor unit according to the present disclosure is a compressor unit including a first compressor, a second compressor, and an oil equalization pipe and a pressure equalization pipe connecting the first compressor and the second compressor, wherein the first compressor and the second compressor include a sealed container, a compression mechanism housed in the sealed container and compressing a refrigerant, an electric motor housed in the sealed container at a position below the compression mechanism and driving the compression mechanism, and an oil reservoir provided in the sealed container at a position below the electric motor and in which refrigeration oil is stored, wherein if a region in the sealed container between the electric motor and the oil reservoir is defined as a lower electric motor region, the oil equalization pipe is in communication with the oil reservoir of the first compressor and the oil reservoir of the second compressor, and the pressure equalization pipe is in communication with the lower electric motor region of the first compressor and the lower electric motor region of the second compressor.

[0009] In the compressor unit according to the present disclosure, the sealed container of the first compressor and the sealed container of the second compressor are connected to each other by a pressure equalizing pipe in the area between the electric motor and the oil reservoir. Therefore, the compressor unit according to the present disclosure can suppress variation in the amount of refrigeration oil stored in the oil reservoir of the first compressor and the amount of refrigeration oil stored in the oil reservoir of the second compressor more than in the past, even when the output of the first compressor and the output of the second compressor are made different.

[0010] Fig. 3 is a longitudinal sectional view of a compressor unit according to an embodiment; Fig. 4 is a sectional view taken along line A-A in Fig. 1; Fig. 5 is an enlarged view of a portion B in Fig. 1; Fig. 6 is an enlarged view of a portion C in Fig. 1; Fig. 7 is an enlarged view of a portion D in Fig. 3; Fig. 8 is an enlarged view of a portion E in Fig. 4; Fig. 9 is an enlarged view of a portion F in Fig. 1; Fig. 10 is an enlarged view of a portion G in Fig. 1;

[0011] Embodiments. Figure 1 is a longitudinal cross-sectional view of a compressor unit according to an embodiment. Figure 2 is a cross-sectional view taken along line A-A in Figure 1. Figure 3 is an enlarged view of section B in Figure 1. Figure 4 is an enlarged view of section C in Figure 1. Figure 5 is an enlarged view of section D in Figure 3. Figure 6 is an enlarged view of section E in Figure 4. Figure 7 is an enlarged view of section F in Figure 1. Figure 8 is an enlarged view of section G in Figure 1.

[0012] The compressor unit 100 according to this embodiment includes a plurality of compressors. Hereinafter, one of the plurality of compressors included in the compressor unit 100 will be referred to as a first compressor 1. Furthermore, of the plurality of compressors included in the compressor unit 100, one of the compressors other than the first compressor 1 will be referred to as a second compressor 2. The first compressor 1 and the second compressor 2 are connected in parallel by an oil equalizing pipe 50 and a pressure equalizing pipe 60. In other words, the compressor unit 100 includes the oil equalizing pipe 50 and the pressure equalizing pipe 60 that connect the first compressor 1 and the second compressor 2.

[0013] The first compressor 1 and the second compressor 2 each include a sealed container 10, a compression mechanism 20, an electric motor 30, and an oil reservoir 14. The sealed container 10 has, for example, a hollow cylindrical shape. The compression mechanism 20 compresses a refrigerant. The compression mechanism 20 is housed in the sealed container 10. The compression mechanism 20 housed in the sealed container 10 compresses the refrigerant that flows into the sealed container 10. For this reason, the first compressor 1 and the second compressor 2 are configured as follows. The first compressor 1 and the second compressor 2 each include a suction pipe 11 and a discharge pipe 13 provided in the sealed container 10. The suction pipe 11 is a pipe that allows the refrigerant to be compressed by the compression mechanism 20 to flow into the sealed container 10. The discharge pipe 13 is a pipe that allows the refrigerant compressed by the compression mechanism 20 to flow out of the sealed container 10.

[0014] Here, the first compressor 1 and the second compressor 2 according to this embodiment are so-called low-pressure shell compressors in which the sealed container 10 is filled with refrigerant before being compressed by the compression mechanism 20. For this reason, in this embodiment, the first compressor 1 and the second compressor 2 are configured as follows. A refrigerant outlet 12 of the suction pipe 11 opens into the interior of the sealed container 10. The compression mechanism 20 draws, through a suction port (not shown), the refrigerant that has flowed into the sealed container 10 from the outlet 12 of the suction pipe 11 and compresses it. The refrigerant inlet of the discharge pipe 13 opens into a discharge muffler 22 that covers a refrigerant discharge hole 21 of the compression mechanism 20. That is, the refrigerant inlet of the discharge pipe 13 is indirectly connected to the discharge hole 21 of the compression mechanism 20 via the discharge muffler 22. The refrigerant compressed by the compression mechanism 20 is discharged from the discharge hole 21 of the compression mechanism 20 into the discharge muffler 22 and flows out of the sealed container 10 through the discharge pipe 13.

[0015] Note that some compressors are so-called high-pressure shell compressors in which a sealed container is filled with refrigerant compressed by a compression mechanism. The first compressor 1 and the second compressor 2 may be high-pressure shell compressors. In this case, a refrigerant outlet 12 of the suction pipe 11 is directly or indirectly connected to a suction port of the compression mechanism 20. A refrigerant inlet of the discharge pipe 13 opens into the inside of the sealed container 10. Also, FIG. 1 illustrates a scroll-type compression mechanism as the compression mechanism 20. However, the compression mechanism 20 is not limited to a scroll-type compression mechanism and may be a compression mechanism other than a scroll-type.

[0016] The electric motor 30 drives the compression mechanism 20. In this embodiment, a rotor of the electric motor 30 and the compression mechanism 20 are connected by a drive shaft 31, and the driving force of the electric motor 30 is transmitted to the compression mechanism 20 via the drive shaft 31. The electric motor 30 is housed in the sealed container 10. Specifically, the electric motor 30 is housed in a position below the compression mechanism 20 in the sealed container 10.

[0017] The oil reservoir 14 is located in the sealed container 10 below the electric motor 30. The oil reservoir 14 is a location where refrigeration oil 3 is stored. The refrigeration oil 3 stored in the oil reservoir 14 is supplied to sliding parts, etc. of the compression mechanism 20, thereby suppressing friction and wear of the sliding parts. Specifically, the first compressor 1 and the second compressor 2 according to this embodiment include a pump 40 provided at the lower end of the drive shaft 31. At least a portion of the pump 40 is immersed in the refrigeration oil 3 stored in the oil reservoir 14. When the pump 40 rotates together with the drive shaft 31, the refrigeration oil 3 stored in the oil reservoir 14 is sucked into the pump 40 through a suction port 41 of the pump 40. The refrigeration oil 3 sucked into the pump 40 passes through an oil flow path 32, etc. formed in the drive shaft 31, and is supplied to the sliding parts, etc. of the compression mechanism 20. The first compressor 1 and the second compressor 2 according to this embodiment are provided with an oil return pipe 23 that returns the refrigeration oil 3 supplied to the compression mechanism 20 to the oil reservoir 14. Specifically, a portion of the refrigeration oil 3 supplied to the compression mechanism 20 flows into the oil return pipe 23 after supplying the sliding parts. The refrigeration oil 3 that has flowed into the oil return pipe 23 falls downward from an outlet 24 of the oil return pipe 23 and is returned to the oil reservoir 14.

[0018] The oil equalization pipe 50 is intended to equalize the amount of refrigeration oil 3 stored in the oil reservoir 14 of the first compressor 1 and the amount of refrigeration oil 3 stored in the oil reservoir 14 of the second compressor 2. The oil equalization pipe 50 is in communication with the oil reservoir 14 of the first compressor 1 and the oil reservoir 14 of the second compressor 2.

[0019] The pressure equalizing pipe 60 is intended to equalize the pressure inside the sealed container 10 of the first compressor 1 and the pressure inside the sealed container 10 of the second compressor 2. The pressure equalizing pipe 60 connects the inside of the sealed container 10 of the first compressor 1 with the inside of the sealed container 10 of the second compressor 2 as follows. First, the region between the electric motor 30 and the oil reservoir 14 in the sealed container 10 is defined as the electric motor lower region 15. That is, the electric motor lower region 15 is the region inside the sealed container 10 that is below the electric motor 30 and above the oil reservoir 14. When the electric motor lower region 15 is defined in this way, the pressure equalizing pipe 60 connects the electric motor lower region 15 of the first compressor 1 and the electric motor lower region 15 of the second compressor 2.

[0020] The pressure equalizing pipe 60 is not limited to any particular configuration as long as it communicates with the lower motor region 15 of the first compressor 1 and the lower motor region 15 of the second compressor 2. In this embodiment, the pressure equalizing pipe 60 is configured as follows: The pressure equalizing pipe 60 includes a main body 61, a first extension pipe 62a housed in the sealed container 10 of the first compressor 1, and a second extension pipe 62b housed in the sealed container 10 of the second compressor 2. The main body 61 is inserted into the oil reservoir 14 of the first compressor 1 and the oil reservoir 14 of the second compressor 2. The first extension pipe 62a communicates with the main body 61 in the oil reservoir 14 of the first compressor 1 and opens into the lower motor region 15 of the first compressor 1. In this embodiment, at least one through-hole 63a is formed in the side surface of the first extension pipe 62a, so that the first extension pipe 62a opens into the lower motor region 15 of the first compressor 1. The second extension pipe 62b communicates with the main body 61 at the oil reservoir 14 of the second compressor 2 and opens into the lower motor region 15 of the second compressor 2. In this embodiment, at least one through-hole 63b is formed in the side surface of the second extension pipe 62b, so that the second extension pipe 62b opens into the lower motor region 15 of the second compressor 2.

[0021] The compressor unit 100 configured as described above operates as follows. When the electric motor 30 of the first compressor 1 is driven, low-temperature, low-pressure refrigerant gas flows from the suction pipe 11 of the first compressor 1 into the sealed container 10 of the first compressor 1. This low-temperature, low-pressure refrigerant gas is drawn into the compression mechanism 20 of the first compressor 1 and compressed to become high-temperature, high-pressure refrigerant gas. This high-temperature, high-pressure refrigerant gas is discharged from the discharge hole 21 of the compression mechanism 20 of the first compressor 1, passes through the discharge muffler 22 and the discharge pipe 13 of the first compressor 1, and flows out of the sealed container 10 of the first compressor 1. The high-temperature, high-pressure refrigerant gas flowing out of the sealed container 10 of the first compressor 1 then circulates through the refrigeration cycle circuit in which the compressor unit 100 is provided.

[0022] Similarly, when the electric motor 30 of the second compressor 2 is driven, low-temperature, low-pressure refrigerant gas flows from the suction pipe 11 of the second compressor 2 into the sealed container 10 of the second compressor 2. This low-temperature, low-pressure refrigerant gas is drawn into the compression mechanism 20 of the second compressor 2 and compressed to become high-temperature, high-pressure refrigerant gas. This high-temperature, high-pressure refrigerant gas is discharged from the discharge hole 21 of the compression mechanism 20 of the second compressor 2, passes through the discharge muffler 22 and the discharge pipe 13 of the second compressor 2, and flows out of the sealed container 10 of the second compressor 2. Then, the high-temperature, high-pressure refrigerant gas flowing out of the sealed container 10 of the second compressor 2 circulates through a refrigeration cycle circuit in which the compressor unit 100 is provided.

[0023] When the first compressor 1 operates as described above, the refrigeration oil 3 stored in the oil reservoir 14 of the first compressor 1 is sucked into the pump 40 through the suction port 41 of the pump 40. The refrigeration oil 3 sucked into the pump 40 passes through the oil flow path 32 formed in the drive shaft 31 of the first compressor 1 and is supplied to the sliding parts of the compression mechanism 20 of the first compressor 1. This suppresses friction and wear of the sliding parts. A portion of the refrigeration oil 3 supplied to the compression mechanism 20 of the first compressor 1 flows into the oil return pipe 23 of the first compressor 1. The refrigeration oil 3 that has flowed into the oil return pipe 23 of the first compressor 1 falls downward from the outlet 24 of the oil return pipe 23 and is returned to the oil reservoir 14 of the first compressor 1. Furthermore, a portion of the refrigeration oil 3 supplied to the compression mechanism 20 of the first compressor 1 flows out of the sealed container 10 of the first compressor 1 together with the refrigerant compressed in the compression mechanism 20 of the first compressor 1, and circulates through the refrigeration cycle circuit in which the compressor unit 100 is provided. The refrigeration oil 3 that has circulated through the refrigeration cycle circuit in which the compressor unit 100 is provided then returns to the oil reservoir 14 of the first compressor 1 or the oil reservoir 14 of the second compressor 2.

[0024] Similarly, when the second compressor 2 is operating, the refrigeration oil 3 stored in the oil reservoir 14 of the second compressor 2 is sucked into the pump 40 from the suction port 41 of the pump 40. The refrigeration oil 3 sucked into the pump 40 passes through an oil flow path 32 formed in the drive shaft 31 of the second compressor 2 and is supplied to sliding parts of the compression mechanism 20 of the second compressor 2. This suppresses friction and wear of the sliding parts. A portion of the refrigeration oil 3 supplied to the compression mechanism 20 of the second compressor 2 flows into the oil return pipe 23 of the second compressor 2. The refrigeration oil 3 that has flowed into the oil return pipe 23 of the second compressor 2 falls downward from the outlet 24 of the oil return pipe 23 and is returned to the oil reservoir 14 of the second compressor 2. Furthermore, a portion of the refrigeration oil 3 supplied to the compression mechanism 20 of the second compressor 2 flows out of the sealed container 10 of the second compressor 2 together with the refrigerant compressed in the compression mechanism 20 of the second compressor 2, and circulates through the refrigeration cycle circuit in which the compressor unit 100 is provided. The refrigeration oil 3 that has circulated through the refrigeration cycle circuit in which the compressor unit 100 is provided then returns to the oil reservoir 14 of the first compressor 1 or the oil reservoir 14 of the second compressor 2.

[0025] When the first compressor 1 and the second compressor 2 are operating as described above, a difference occurs between the amount of refrigeration oil 3 stored in the oil reservoir 14 of the first compressor 1 and the amount of refrigeration oil 3 stored in the oil reservoir 14 of the second compressor 2. In this case, an increase in the amount of refrigeration oil 3 flows out of the compressor having more refrigeration oil 3 stored in the oil reservoir 14, and the amount of refrigeration oil 3 flowing out of the compressor unit 100 also increases. As a result, an increase in the amount of refrigeration oil 3 adhering to the heat exchangers of the refrigeration cycle circuit decreases, resulting in a decrease in the heat exchange performance of the heat exchangers of the refrigeration cycle circuit. Furthermore, if a difference occurs between the amount of refrigeration oil 3 stored in the oil reservoir 14 of the first compressor 1 and the amount of refrigeration oil 3 stored in the oil reservoir 14 of the second compressor 2, the amount of refrigeration oil 3 supplied to the sliding parts of the compression mechanism 20 of the compressor having less refrigeration oil 3 stored in the oil reservoir 14 decreases, resulting in a decrease in the reliability of the compressor.

[0026] For this reason, the compressor unit 100 is configured so that the refrigeration oil 3 flows through the oil equalization pipe 50 from the compressor having more refrigeration oil 3 stored in the oil reservoir 14 to the compressor having less refrigeration oil 3 stored in the oil reservoir 14. This makes it possible to prevent a difference from occurring between the amount of refrigeration oil 3 stored in the oil reservoir 14 of the first compressor 1 and the amount of refrigeration oil 3 stored in the oil reservoir 14 of the second compressor 2.

[0027] Here, the compressor unit 100 may have different outputs for the purpose of controlling the capacity of the compressor unit 100, etc. In this case, the amount of refrigerant oil returning from the refrigeration cycle circuit to each compressor varies depending on the difference in output between the compressors. For example, assume that the first compressor 1 is operating and the second compressor 2 is stopped. In this case, the refrigerant oil 3 flowing out of the compressor unit 100 into the refrigeration cycle circuit returns only to the first compressor 1 that is operating.

[0028] Furthermore, when the compressor outputs are made different, if the compressor unit 100 does not include the pressure equalizing pipe 60, a difference in pressure occurs in the sealed containers of the compressors. Due to the pressure difference in the sealed containers of the compressors, more refrigeration oil 3 accumulates in the compressor with a lower pressure in its sealed container, resulting in a difference in the amount of refrigeration oil accumulated in the oil reservoir 14 of each compressor. For example, assume that the compressor unit 100 according to this embodiment does not include the pressure equalizing pipe 60, the first compressor 1 is operating, and the second compressor 2 is stopped. In such a case, the pressure in the sealed container 10 of the operating first compressor 1 is lower than that of the stopped second compressor 2. Therefore, more refrigeration oil 3 accumulates in the oil reservoir 14 of the operating first compressor 1 than that of the stopped second compressor 2. Therefore, the compressor unit 100 according to this embodiment uses the pressure equalizing pipe 60 to equalize the pressure inside the sealed container 10 of the first compressor 1 and the pressure inside the sealed container 10 of the second compressor 2. That is, the compressor unit 100 according to this embodiment uses the pressure equalizing pipe 60 to prevent a difference from occurring between the amount of refrigeration oil 3 stored in the oil reservoir 14 of the first compressor 1 and the amount of refrigeration oil 3 stored in the oil reservoir 14 of the second compressor 2, even when the outputs of the compressors are made different.

[0029] Meanwhile, even in conventional compressor units with multiple compressors connected in parallel by oil equalizing pipes, a system has been proposed in which the multiple compressors are connected in parallel by pressure equalizing pipes and oil equalizing pipes. In such conventional compressor units with multiple compressors connected by pressure equalizing pipes and oil equalizing pipes, the pressure equalizing pipes are connected to a region above the compression mechanisms within the sealed containers of the multiple compressors. That is, in conventional compressor units with multiple compressors connected by pressure equalizing pipes and oil equalizing pipes, the pressure equalizing pipes are connected to a region above the electric motors within the sealed containers of the multiple compressors. The electric motors have flow paths that connect the spaces above and below the motors. However, these flow paths are narrow, and pressure loss prevents fluid from flowing efficiently through these paths. Therefore, in conventional compressor units with multiple compressors connected by pressure equalizing pipes, even if pressure equalizing pipes are used to reduce the pressure difference within the sealed containers of each compressor, the pressure difference remains large in the oil reservoir located below the electric motors. In other words, conventional compressor units equipped with multiple compressors connected by pressure and oil equalization pipes have not yet been able to sufficiently suppress variations in the amount of refrigeration oil stored in the oil reservoirs of the compressors when the outputs of the compressors are varied. For example, suppose the pressure difference between the oil reservoirs of two compressors is 0.001 MPa. In this case, the oil level difference between the oil reservoirs of the two compressors is 10 cm.

[0030] On the other hand, in the compressor unit 100 according to the present embodiment, the sealed container 10 of the first compressor 1 and the sealed container 10 of the second compressor 2 are connected to each other by a pressure equalizing pipe 60 in the motor lower region 15, which is a region between the electric motor 30 and the oil reservoir 14. Therefore, the compressor unit 100 according to the present embodiment can more effectively prevent variations in the amount of refrigeration oil 3 stored in the oil reservoir 14 of the first compressor 1 and the amount of refrigeration oil 3 stored in the oil reservoir 14 of the second compressor 2, even when the outputs of the first compressor 1 and the second compressor 2 are different. That is, the compressor unit 100 according to the present embodiment can more effectively prevent a decrease in the heat exchange performance of the heat exchangers in the refrigeration cycle circuit than a conventional compressor unit including multiple compressors connected by a pressure equalizing pipe and an oil equalizing pipe. Furthermore, the compressor unit 100 according to the present embodiment can more effectively prevent a decrease in the reliability of the compressors than a conventional compressor unit including multiple compressors connected by a pressure equalizing pipe and an oil equalizing pipe.

[0031] Furthermore, the compressor unit 100 according to this embodiment can achieve the following advantages over a conventional compressor unit having multiple compressors connected by pressure equalizing pipes and oil equalizing pipes. The heat exchangers and refrigerant piping that make up the refrigeration cycle circuit are often located at the top of the compressor unit. Therefore, conventional compressor units having multiple compressors connected by pressure equalizing pipes and oil equalizing pipes are subject to design constraints when providing pressure equalizing pipes. On the other hand, the compressor unit 100 according to this embodiment allows the pressure equalizing pipe 60 to be located lower than the pressure equalizing pipes of conventional compressor units having multiple compressors connected by pressure equalizing pipes and oil equalizing pipes. Therefore, the compressor unit 100 according to this embodiment offers greater design freedom than conventional compressor units having multiple compressors connected by pressure equalizing pipes and oil equalizing pipes.

[0032] In this embodiment, the pressure equalizing pipe 60 of the compressor unit 100 is composed of the main body 61, the first extension pipe 62a, and the second extension pipe 62b. Therefore, in the compressor unit 100 according to this embodiment, the pressure equalizing pipe 60 can be disposed further downward. Therefore, the compressor unit 100 according to this embodiment has a greater degree of freedom in design.

[0033] Furthermore, in the first compressor 1 and the second compressor 2 of the compressor unit 100 according to this embodiment, when the inside of the sealed container 10 is observed from above, the oil equalizing pipe 50 and the pressure equalizing pipe 60 open at positions shown in FIG. 2 . Specifically, when the inside of the sealed container 10 is observed from above, an imaginary line passing through the refrigerant outlet 12 of the suction pipe 11 and the refrigeration oil outlet 24 of the oil return pipe 23 is defined as an imaginary line 16. When the inside of the sealed container 10 is observed from above, the region inside the sealed container 10 divided into two by the imaginary line 16 is defined as a divided region. Hereinafter, as shown in FIG. 2 , one of the two divided regions is defined as divided region 17, and the other of the two divided regions is defined as divided region 18. When the divided regions are defined in this manner, when the inside of the sealed container 10 of the first compressor 1 is observed from above, the oil equalizing pipe 50 and the pressure equalizing pipe 60 open to different divided regions. Furthermore, when the interior of the sealed container 10 of the second compressor 2 is observed from above, the oil equalizing pipe 50 and the pressure equalizing pipe 60 open to different divided regions. In the first compressor 1 and the second compressor 2 illustrated in Fig. 2, the oil equalizing pipe 50 opens to divided region 17, and the pressure equalizing pipe 60 opens to divided region 18.

[0034] The surface of the refrigerating machine oil 3 stored in the oil reservoir 14 fluctuates locally due to the refrigerant gas flowing into the sealed container 10 from the suction pipe 11 and the refrigerating machine oil 3 flowing out from the oil return pipe 23. In this case, because the oil equalizing pipe 50 and the pressure equalizing pipe 60 are open as described above, it is possible to prevent local fluctuations in the surface of the refrigerating machine oil 3 stored in the oil reservoir 14 from affecting the flow of the refrigerating machine oil 3 in the oil equalizing pipe 50 and the flow of the refrigerant gas in the pressure equalizing pipe 60. Therefore, because the oil equalizing pipe 50 and the pressure equalizing pipe 60 are open as described above, it is possible to further prevent variations in the amount of refrigerating machine oil 3 stored in the oil reservoir 14 of the first compressor 1 and the amount of refrigerating machine oil 3 stored in the oil reservoir 14 of the second compressor 2.

[0035] 7 and 8 , in the compressor unit 100 according to this embodiment, the oil equalization pipe 50 is connected to the first compressor 1 and the second compressor 2. Specifically, the oil equalization pipe 50 is connected to the oil reservoir 14 of the first compressor 1 at a position above the suction port 41 of the pump 40 of the first compressor 1. The oil equalization pipe 50 is also connected to the oil reservoir 14 of the second compressor 2 at a position above the suction port 41 of the pump 40 of the second compressor 2. The compressor unit 100 configured in this manner improves the reliability of securing the amount of refrigeration oil 3 necessary for starting and driving the compressors in the first compressor 1 and the second compressor 2. Therefore, the compressor unit 100 configured in this manner further improves the reliability of the first compressor 1 and the second compressor 2.

[0036] When the oil equalizing pipe 50 is connected to the first compressor 1 and the second compressor 2 as described above, the oil equalizing pipe 50 is preferably configured as follows. Specifically, the oil equalizing pipe 50 is preferably formed with a first through-hole 51a that connects the oil equalizing pipe 50 to the oil reservoir 14 of the first compressor 1, and a second through-hole 51b that connects the oil equalizing pipe 50 to the oil reservoir 14 of the second compressor 2. The first through-hole 51a and the second through-hole 51b are preferably open upward. This allows the oil equalizing pipe 50 to be positioned further downward, improving the flexibility in designing the compressor unit 100.

[0037] As described above, the compressor unit 100 according to this embodiment is a compressor unit including a first compressor 1, a second compressor 2, and an oil equalizing pipe 50 and a pressure equalizing pipe 60 connecting the first compressor 1 and the second compressor 2. The first compressor 1 and the second compressor 2 each include a sealed container 10, a compression mechanism 20, an electric motor 30, and an oil reservoir 14. The compression mechanism 20 is housed in the sealed container 10 and compresses a refrigerant. The electric motor 30 is housed in the sealed container 10 below the compression mechanism 20 and drives the compression mechanism 20. The oil reservoir 14 is located below the electric motor 30 in the sealed container 10 and is a location where refrigeration oil 3 is stored. A region in the sealed container 10 between the electric motor 30 and the oil reservoir 14 is defined as a lower motor region 15. The oil equalizing pipe 50 is in communication with the oil reservoir 14 of the first compressor 1 and the oil reservoir 14 of the second compressor 2. The pressure equalizing pipe 60 is in communication with the lower motor region 15 of the first compressor 1 and the lower motor region 15 of the second compressor 2.

[0038] As described above, the compressor unit 100 configured in this manner can suppress variation in the amount of refrigeration oil 3 stored in the oil reservoir 14 of the first compressor 1 and the amount of refrigeration oil 3 stored in the oil reservoir 14 of the second compressor 2 more than in the past.

[0039] REFRIGERATION SYSTEM, 10 AIR CONTAINER, 11 SUPPLY PIPE, 12 OUTLET, 13 DISCHARGE PIPE, 14 OIL RESERVOIR, 15 LOWER REGION OF MOTOR, 16 VIRTUAL LINE, 17 DIVIDED REGION, 18 DIVIDED REGION, 20 COMPRESSION MECHANISM, 21 DISCHARGE HOLE, 22 DISCHARGE MUFFLER, 23 OIL RETURN PIPE, 24 OUTLET, 30 MOTOR, 31 DRIVE SHAFT, 32 OIL FLOW PLANE, 40 PUMP, 41 SUPPLY PORT, 50 OIL EQUALIZING PIPE, 51a FIRST THROUGHPUT, 51b SECOND THROUGHPUT, 60 EQUALIZING PIPE, 61 BODY, 62a FIRST EXTENSION PIPE, 62b SECOND EXTENSION PIPE, 63a THROUGHPUT, 63b THROUGHPUT, 100 COMPRESSOR UNIT.

Claims

1. A compressor unit comprising: a first compressor, a second compressor, and an oil equalizing pipe and a pressure equalizing pipe connecting the first compressor and the second compressor, wherein the first compressor and the second compressor comprise: a sealed container; a compression mechanism housed in the sealed container and compressing a refrigerant; an electric motor housed in the sealed container at a position below the compression mechanism and driving the compression mechanism; and an oil reservoir provided in the sealed container at a position below the electric motor and in which refrigeration oil is stored, wherein when a region in the sealed container between the electric motor and the oil reservoir is defined as a lower motor region, the oil equalizing pipe is in communication with the oil reservoir of the first compressor and the oil reservoir of the second compressor, and the pressure equalizing pipe is in communication with the lower motor region of the first compressor and the lower motor region of the second compressor.

2. The compressor unit according to claim 1, wherein the first compressor and the second compressor comprise: a suction pipe that flows refrigerant compressed by the compression mechanism into the sealed container; and an oil return pipe that returns refrigeration oil supplied to the compression mechanism to the oil reservoir; and when an area inside the sealed container that is divided into two by an imaginary line passing through a refrigerant outlet of the suction pipe and a refrigeration oil outlet of the oil return pipe is defined as a divided area when the inside of the sealed container is observed from above, when the inside of the sealed container of the first compressor is observed from above, the oil equalizing pipe and the pressure equalizing pipe open to different divided areas, and when the inside of the sealed container of the second compressor is observed from above, the oil equalizing pipe and the pressure equalizing pipe open to different divided areas.

3. A compressor unit as described in claim 1 or claim 2, wherein the pressure equalizing pipe comprises: a main body; a first extension pipe housed in the sealed container of the first compressor; and a second extension pipe housed in the sealed container of the second compressor, wherein the main body is inserted into the oil reservoir of the first compressor and the oil reservoir of the second compressor, the first extension pipe communicates with the main body at the oil reservoir of the first compressor and opens into the lower motor area of ​​the first compressor, and the second extension pipe communicates with the main body at the oil reservoir of the second compressor and opens into the lower motor area of ​​the second compressor.

4. A compressor unit as described in any one of claims 1 to 3, wherein the first compressor and the second compressor are equipped with pumps that draw refrigeration oil stored in the oil reservoir from a suction port, and the oil equalization pipe is connected to the oil reservoir of the first compressor at a position above the suction port of the pump of the first compressor, and is connected to the oil reservoir of the second compressor at a position above the suction port of the pump of the second compressor.

5. A compressor unit as described in claim 4, wherein the oil equalizing pipe is formed with a first through hole that connects the oil equalizing pipe to the oil reservoir of the first compressor and a second through hole that connects the oil equalizing pipe to the oil reservoir of the second compressor, and the first through hole and the second through hole open upward.

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